Volume control independent from the system (alsamixer)

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1

Hi,

Is there anyway to control the volume of the rhasspy by software instead of getting the volume level from alsamixer?
I wanted to have this independently because I have other sound components running on the same raspberry pi each with its own volume settings and I want to leave the alsamixer on the top volume.
But since I cannot control the volume level on rhasspy it is just too loud.

Current audio components on the rpi:

  • shairport-sync which uses the asound/alsamixer direct volume level but controllable on the physical volume button on iOS devices
  • mopidy which has a “wrapper” in which I can set a different volume level than the asound/alsamixer volume level (up to its maximum)
  • rhasspy which uses the asound/alsamixer direct volume level. It is here that I would like to have something similar to mopidy where I could set a lower volume than the one defined on the sound/alsamixer direct volume level.

Thanks!

2

Haven’t done it but presuming you could use a softvol.

https://alsa.opensrc.org/Softvol for a specific pcm maybe

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3

Thanks for the tip!

I was able to create the new softvol device (named rhasspysnd as you can see below) and mixer but Rhasspy doesn’t see that device:

pi@livingroom:~ $ aplay -L
null
Discard all samples (playback) or generate zero samples (capture)
jack
JACK Audio Connection Kit
pulse
PulseAudio Sound Server
playback
ac108
default
output
rhasspysnd
sysdefault:CARD=Headphones
bcm2835 Headphones, bcm2835 Headphones
Default Audio Device
dmix:CARD=Headphones,DEV=0
bcm2835 Headphones, bcm2835 Headphones
Direct sample mixing device
dsnoop:CARD=Headphones,DEV=0
bcm2835 Headphones, bcm2835 Headphones
Direct sample snooping device
hw:CARD=Headphones,DEV=0
bcm2835 Headphones, bcm2835 Headphones
Direct hardware device without any conversions
plughw:CARD=Headphones,DEV=0
bcm2835 Headphones, bcm2835 Headphones
Hardware device with all software conversions
usbstream:CARD=Headphones
bcm2835 Headphones
USB Stream Output
usbstream:CARD=seeed4micvoicec
seeed-4mic-voicecard
USB Stream Output

And on Rhasspy:

rhasspy
rhasspy823Ă—425 89.2 KB

If I try to use it through aplay on the rpi it works ok:
aplay --device rhasspysnd a.wav

Maybe Rhasspy isn’t loading the softvol type cards right? Can we make it load those?

4

Dunno but softvols can be really confusing as they don’t exist until after you play that pcm chain.
I am not sure on the setup as haven’t done much with them but presumed you could have a pcm chain with the softvol in it for rhasspy that just has the initial alsa device as a slave.

I think on boot in the start-up script you need to aplay the pcm with the softvol once and then it should be there from then aplay -d for duration is it just have a second burst of some wav before rhasspy loads.

Also with asla pcms you have to add the description tag to that pcm. Have a look through the forum as there is an example somewhere.

Think its hint.description

hint.description "Mic1 loopback 0,1,0"

or this format in the ever confusing alsa formatting

hint {
                description "Mic2 loopback 0,1,1"
        }

As sometimes without they don’t list for some reason without, just change the description to what you need.

5

Hi,
Sorry I missed posting my config. Making the change you mentioned still doesn’t work:

pi@livingroom:~ $ cat ~/.asoundrc
pcm.rhasspysnd {
type softvol
slave.pcm “sysdefault”
control.name “rhasspysndctrl”
control.card 0
hint.description “Rhasspy”
}

It already shows the description:
pi@livingroom:~ $ aplay -L
rhasspysnd
Rhasspy

But on the rhasspy interface it still isn’t available. (I have already added an aplay command to my rpi /etc/profile so that on boot it runs it):
pi@livingroom:~ $ cat /etc/profile
aplay --device rhasspysnd output.wav

6

I always refer to this article when fiddling with alsa.

The softvol is a control so like the article create an end PCM where the chain continues and the softvol is a slave.

Otherwise dunno but maybe someone else will post as remember something mentioned in the forum about PCMs needing a description or tag line to turn up in Rhasspy and just plain forget what and where.

7

Finally solved. Was missing passing the -v “/etc/asound.conf:/etc/asound.conf” on the docker run

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